I would stick with the caliber and load I normally carry. Shot placement is going to be more important than the particular bullet. Getting a clear shot at the bad guy in a church full of panicked people is probably going to be more of a problem than over penetration.

Every time I thought I might need my revolver while attending church the "problem" was a disturbed homeless person. Fortunately the pastor was very good at dealing with those people, and calmed them down before things got out of hand and anything bad happened.

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Wheel guns are real guns.